"They asked me to get involved but I couldn't stand up," says the heartbroken Boyzone manager. "I'd break down.
"The emotions and nerves would be worse than any X Factor show. I don't like real life – that's why I like the pop business, it's not real. The funeral will hit me hard," he told the Sun.
Louis will miss The X Factor's Saturday night show to attend the service in Dublin with Stephen's family and his bandmates.
Keith Duffy, Ronan Keating, Mikey Graham and Shane Lynch are understood to be flying to Majorca to accompany Stephen's casket back to the UK. They also announced on their website there will be a memorial service for the singer on a date still to be decided.
As friends and family struggle to come to terms with their loss, they can take comfort in comments he made in one of his final interviews.
"I know there's a heaven," he told the Irish Mirror, a fortnight before his death.
The star, who was 33 when he died, said he was also set on adopting a baby with long-term partner Andrew Cowles.
"I won't be truly complete until I have children. That's my biggest dream," he revealed.